1 files changed, 40 insertions, 0 deletions
diff --git a/packages/backend/src/core/AppLockService.ts b/packages/backend/src/core/AppLockService.ts
new file mode 100644
index 0000000000..f3c345493b
--- /dev/null
+++ b/packages/backend/src/core/AppLockService.ts
@@ -0,0 +1,40 @@
+import { promisify } from 'node:util';
+import { Inject, Injectable } from '@nestjs/common';
+import redisLock from 'redis-lock';
+import Redis from 'ioredis';
+import { DI } from '@/di-symbols.js';
+
+/**
+ * Retry delay (ms) for lock acquisition
+ */
+const retryDelay = 100;
+
+@Injectable()
+export class AppLockService {
+	#lock: (key: string, timeout?: number) => Promise<() => void>;
+
+	constructor(
+		@Inject(DI.redis)
+		private redisClient: Redis.Redis,
+	) {
+		this.#lock = promisify(redisLock(this.redisClient, retryDelay));
+	}
+
+	/**
+	 * Get AP Object lock
+	 * @param uri AP object ID
+	 * @param timeout Lock timeout (ms), The timeout releases previous lock.
+	 * @returns Unlock function
+	 */
+	public getApLock(uri: string, timeout = 30 * 1000): Promise<() => void> {
+		return this.#lock(`ap-object:${uri}`, timeout);
+	}
+
+	public getFetchInstanceMetadataLock(host: string, timeout = 30 * 1000): Promise<() => void> {
+		return this.#lock(`instance:${host}`, timeout);
+	}
+
+	public getChartInsertLock(lockKey: string, timeout = 30 * 1000): Promise<() => void> {
+		return this.#lock(`chart-insert:${lockKey}`, timeout);
+	}
+}